Method for determining at least one target information of a target object of a sensor system based on an environmental reconstruction of the sensor system's environment, as well as the sensor system and vehicle.
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- VOLKSWAGEN AG
- Filing Date
- 2024-02-19
- Publication Date
- 2026-06-25
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
The present invention relates to a method for determining at least one target information of a target object, a sensor system comprising several transmitting elements and several receiving elements. Furthermore, the invention relates to a sensor system with multiple transmitting antennas, multiple receiving antennas and an electronic computing device. Furthermore, the invention relates to a vehicle with a corresponding sensor system. For example, WO 2022 / 228916 A1 discloses a radar sensor device designed as a single-chip system. This system includes a transmit path, a receive path, an optical input, an optical output, an antenna, and a digital interface unit. Furthermore, DE 10 2022 202028 A discloses a radar sensor device for a vehicle. This device comprises a transmitter for transmitting radar signals and a receiver for receiving signals. The radar sensor device includes at least one antenna structure, which has two opposing and spaced-apart metallic structural elements, wherein at least one metallic structural element is an antenna structure that generates the electrical radar signal and modulates the received electrical signal. Furthermore, US 10,686,523 B1 discloses a photonically integrated circuit which has both optical and electrical components to perform optical and electrical signal processing. Furthermore, DE 10 2020 123 293 A1 discloses a method for signal processing of radar signals from a radar system, in particular a vehicle radar system, preferably an automotive radar system, with at least two radar units arranged apart from each other. DE 10 2019 126 988 A1 discloses a method for reducing interference in a radar system having at least two, in particular spatially separated, transmit-receive units, wherein the method comprises the following steps: - a transmission step in which a first transmit signal of the first transmit-receive unit is sent to a second transmit-receive unit and a second transmit signal of the second transmit-receive unit is sent to the first transmit-receive unit via a radio channel, wherein the transmit signals are modulated according to an orthogonal frequency division multiplexing method;and a pre-correction step in which correction values are determined from the received transmitted signals, and in particular exchanged between the transmitting and receiving stations, wherein the received transmitted signals are post-processed based on the correction values, so that the influences of disturbances, in particular phase noise and / or a temporal offset and / or unknown initial phase positions, are reduced, preferably compensated. Furthermore, the invention describes a radar system and a use of a method. DE 10 2014 104 273 A1 describes a method in a radar system in which a first signal is generated in a first non-coherent transmit-receive unit and transmitted, in particular broadcast, via a path, in a further, in particular second, non-coherent transmit-receive unit a first signal is generated and transmitted, in particular broadcast, via the path, in the first transmit-receive unit a comparison signal is formed from its first signal and from such a first signal received by the further transmit-receive unit via the path, and in the further transmit-receive unit a further comparison signal is formed from its first signal and from such a first signal received by the first transmit-receive unit via the path, wherein the further comparison signal is transmitted, in particular communicated, from the further transmit-receive unit to the first transmit-receive unit. From DE 10 2016 210 771 B3, a motor vehicle with a detection device for angle-resolved detection of the motor vehicle's surroundings by means of a radar method is known, wherein the detection device comprises at least one antenna device which is configured to transmit signals and / or to receive signals, and a central unit, wherein the central unit is connected to the antenna device via at least one optical fiber for optical signal transmission, through which control signals of the central unit for controlling the transmission of the signals and / or the received signals or signals derived from them can be transmitted. One object of the present invention is to improve the detection of a target object in the environment of a sensor system by obtaining more comprehensive information concerning the target object and the environment. This task is solved by a method, a sensor system, and a vehicle according to the independent patent claims. Meaningful further developments arise from the dependent patent claims. One aspect of the invention relates to a method for determining at least one target information of a target object of a sensor system comprising multiple transmitting antennas and multiple receiving antennas, wherein: - In particular, in a transmission process, multiple frequency-shifted electrical outgoing signals are simultaneously transmitted from the multiple transmitting antennas into an environment; - In particular, electrical receiving signals based on the transmitted electrical outgoing signals are received by the multiple receiving antennas; - In particular, based on the received electrical receiving signals, the antenna positions of the multiple transmitting antennas, and the antenna positions of the multiple receiving antennas, a virtual antenna array comprising multiple virtual receiving antennas is generated; - In particular, an environmental reconstruction of the environment is performed based on the virtual antenna array.and – In particular, at least one target piece of information is determined based on the environmental reconstruction. The proposed method allows for more efficient and, in particular, more versatile use of a sensor system, as target information about a target object in the sensor system's environment can be acquired more effectively and precisely. The virtual antenna array is generated by simultaneously transmitting multiple frequency-shifted electrical signals into the environment for each transmission request. In other words, for each transmission, the sensor system emits an electrical signal using multiple or a predetermined number of transmitting antennas, i.e., transmitting elements. These electrical signals have different frequencies, resulting in frequency shifts between them.Simultaneous transmission and emission of electrical signals with different frequencies allows for improved and, in particular, more efficient generation of a virtual antenna array. The generation of virtual antenna arrays is especially advantageous for signal processing and thus for environmental sensing. Based on the transmitted and received signals, several virtual antenna elements or a virtual antenna array can be deployed, thereby increasing, for example, the resolution of the sensor system. The electrical signals emitted in the vicinity of the transmitting system can in turn be reflected or back-radiated accordingly, so that at least some electrical receiving signals corresponding to the electrical signals emitted are received by several or at least some of the several receiving antennas. For the generation or creation of the virtual antenna array, particularly from a system perspective, the received electrical signals, the respective real antenna positions of the multiple, especially real, transmitting antennas, and the real antenna positions of their multiple, especially real, receiving antennas can be taken into account. The virtual antenna array offers the significant advantage of being able to incorporate more transmitting and receiving antennas compared to the physical antennas of a real antenna array. This results in a much larger number of virtual transmitting and receiving antennas, often many times greater than the number of physical transmitting and receiving antennas. Consequently, the physical sensor system can be used and manufactured more easily and, in particular, at a reduced cost. Furthermore, the virtual antenna array enables environmental reconstruction to obtain more comprehensive information about the target object, especially its environment, and to enhance the informational content of target information regarding potential target objects.In addition to a single transmission, a multitude of successive transmissions and the corresponding transmitted and received signals can be considered. This allows, in particular, the detection of the spatial extent of the target object within its environment, such as in a vehicle environment when using the sensor system in the automotive sector. Environmental reconstruction, i.e., a virtual three-dimensional model of the environment based on the virtual antenna array, enables the reliable detection of extended structures, such as target objects, in the vicinity of the sensor system. Environmental reconstruction allows, for example, a better estimation of the height profile of these structures, such as the target object. In particular, the present method offers advantages in terms of increased user-friendliness during the data acquisition process and, for example, improved reliability of the sensor system regardless of the weather conditions in the sensor system's environment. The virtual antenna array and the resulting environmental reconstruction enable robust environmental sensing for mapping and localization. By simultaneously emitting frequency-shifted signals and generating the virtual antenna array, descriptors within a three-dimensional environmental model, such as the environmental reconstruction, can be detected for mapping and localization purposes. The proposed method is particularly useful when the sensor system is used in the automotive sector. There, it can be used primarily to detect objects located next to a moving vehicle, especially moving objects. Using the proposed method, the transmitting and receiving antennas can be positioned laterally on the vehicle, for example, along the B-pillar. This allows for improved environmental detection by radiating signals laterally from the vehicle, specifically towards the passenger side and the front. For environmental reconstruction, i.e., the modeling of a three-dimensional virtual environment based on the real environment, the simultaneous transmission of frequency-shifted external signals can be performed at specific intervals during the vehicle's movement. This allows for continuous environmental monitoring using one or more virtual antenna arrays. This enables the reconstruction of the environment. Based on this environmental reconstruction, target objects within it can be detected more accurately and precisely, thus expanding and enriching the information available for targets, such as radar targets. It is intended that each received electrical signal, assigned to a specific virtual receiving antenna of the virtual antenna array, is mixed with a carrier signal on which the multiple frequency-shifted electrical outgoing signals are based. In other words, the electrical received signal for the corresponding receiving antennas is mixed with the original transmitted signal, specifically the electrical carrier signal. Based on the carrier signal, which can be provided by a central processing unit of the sensor system, the frequency-shifted electrical outgoing signals can be generated. Put another way, the respective received signal can be mixed by multiplying it by the original transmitted signal, i.e., the carrier signal.Thus, a corresponding mixed signal such as a beat signal can be generated here, which is needed for the calculation of the virtual antenna array and especially for the environmental reconstruction. It is intended that a distance spectrum is determined for each virtual receiving antenna based on the received signal associated with that antenna and mixed with the carrier signal. Using this distance spectrum, which can also be referred to as a "range spectrum," distance information can be generated or calculated for each virtual receiving antenna based on the mixed received signal. In particular, a distance spectrum can be generated for each virtual receiving antenna. Thus, corresponding distance information regarding each virtual receiving antenna can be provided. The system intends to decompose the distance spectrum of each virtual receiving antenna into sub-spectra depending on the corresponding transmitted electrical signal and the transmitting antenna emitting this signal. This allows for the decomposition of the distance spectrum based on the corresponding real transmitting antenna. Thus, selection is performed based on the real transmitting antenna and, in particular, the frequency deviations of the respective transmitting antenna. This is because the transmitting antennas emit electrical signals that are frequency-shifted relative to each other, so that each signal transmitted between two transmitting antennas exhibits a frequency deviation compared to the others.This allows for the selection of a frequency spectrum for each virtual receiving antenna based on the respective real transmitting antenna that emitted the corresponding outgoing signal. This is particularly advantageous for environmental reconstruction and especially for three-dimensional environmental modulation. In one embodiment, the partial spectra of each virtual receiving antenna are projected onto a virtual, spatial grid model for environmental reconstruction. This model allows for the three-dimensional modeling of the environment, depending on the transmitting antenna corresponding to each partial spectrum. In other words, the partial spectra of each virtual receiving antenna can be projected onto a spatial grid model. For example, a position can be defined as the starting point for each transmission. This position can then be used as a reference for generating the virtual spatial grid model. In other words, the grid model enables virtual, software-based modulation and reconstruction of the environment.Thus, target objects can be projected into the spatial grid model by the system based on the received signals and the corresponding sub-spectra, which contain distance information regarding the target object. The spatial extent of the target object can be characterized or provided based on the various sub-spectra. This is particularly advantageous for determining target information, as it allows for the determination of extensive information regarding the environment and, in particular, the target object or multiple target objects. For example, the sub-spectra of each virtual receiving antenna can be projected onto a discrete, three-dimensional volume grid, such as the virtual spatial grid model, depending on the transmitting antenna corresponding to the respective sub-spectrum. This can be advantageously used for environmental reconstruction.In one embodiment, the virtual spatial grid model is divided into several volume pixels. Each volume pixel is assigned a subspectrum of the subspectra of a respective virtual receiving antenna based on a relationship between the corresponding transmitting antenna and the virtual spatial grid model. Using the respective subspectra, which contain distance information, each volume pixel can be populated with information. In other words, each volume pixel of the grid model contains corresponding information, which in turn allows for the determination of relevant information about the target object. For example, the grid model can be square, allowing the individual volume pixels to be cuboid. Depending on the grid model, and especially the environment, any number of volume pixels can be combined to generate the grid model. Thus, depending on the virtual antenna array, at least some of the volume pixels can be provided with information regarding environmental perception and, in particular, the target direction. In one embodiment, phase compensation filtering is performed for each sub-spectrum to compensate for its phase position in the virtual, spatial peak model. This phase compensation filtering is based on the transmitting antenna of the virtual receiving antenna corresponding to that sub-spectrum and the frequency of the electrical signal emitted by the transmitting antenna. Thus, each sub-spectrum can be filtered to compensate for its phase position.The filtering process can take into account the transmitting antenna corresponding to the subspectroscopy, the virtual receiving antenna of the subspectroscopy, and the frequency of the transmitted electrical signal from the corresponding transmitting antenna. In particular, phase compensation filtering can compensate for distance-related phase shifts of the projected or calculated subspectroscopy onto the grid model. This allows for improved environmental modeling and reconstruction. In one embodiment, the individual sub-spectra of each receiving antenna, where phase compensation filtering has been performed, are integrated. This results in the integration of the filtered projections of all sub-spectra. Consequently, a data structure filtered for each receiving antenna can be assigned, corresponding, for example, to a measurement position and the spatial grid model or grid model at that measurement position. Another aspect of the invention relates to a sensor system with multiple transmitting antennas, multiple receiving antennas, and an electronic computing device, wherein the sensor system is configured to perform a method according to the previous aspect or an advantageous embodiment thereof. Thus, the aforementioned method can be carried out with the sensor system just described. The sensor system can be used, for example, to reconstruct the environment, particularly a three-dimensional environment. Specifically, this reconstruction can be achieved by constructing a synthetic aperture and reconstructing the received signals using a virtual antenna array. In particular, the sensor system can be used to perform frequency conversion of a terahertz carrier signal into the gigahertz frequency range after optical signal transmission and reception of gigahertz signals with modulation on terahertz carrier signal and vice versa. In particular, the proposed sensor system can be used in motor vehicles. Specifically, it can be deployed in vehicles that are at least partially autonomous, and especially in fully autonomous vehicles. For such automated driving, reliable environmental perception is essential, which the sensor system can provide. The environment can be captured using sensors such as radar, lidar, and cameras. These are just a few examples of the sensor system's potential applications. The sensor system enables a comprehensive 360-degree, three-dimensional capture of the environment, allowing for the detection of all static and dynamic objects. The sensor system can, for example, be used to improve environmental perception regarding the side areas of a vehicle. The sensor system can be used as an alternative to lidar, since lidar plays a key role in redundant, robust environmental sensing, as this type of sensor can be used more precisely in environmental sensing, measuring distances and angles, and also for classification. In particular, the sensor system can be used in vehicles that are at least partially autonomous, and especially in fully autonomous vehicles. However, to enable such automated driving, reliable environmental perception is essential. This involves capturing the surroundings using sensors such as radar, lidar, or cameras. A comprehensive 360-degree, three-dimensional view of the environment is particularly important, allowing all static and dynamic objects to be detected. The sensor system can be used for this purpose. However, these lidar sensors are expensive and complex to design.Particularly problematic is 360-degree three-dimensional environmental sensing, as it either requires many smaller individual sensors, which typically operate with numerous individual light sources and detector elements, or large lidar sensors. Furthermore, lidar sensors are susceptible to weather conditions such as rain, fog, or direct sunlight. This sensor system can address these issues. Radar sensors and sensor systems are well-established in automotive engineering and reliably deliver data in all weather conditions. Even poor visibility, such as rain, fog, snow, dust, or darkness, hardly affects their detection reliability. However, according to the current state of the art, the resolution is limited; in particular, commercially available radar systems only have an angular resolution of approximately 2 degrees. To meet the requirements for increased automation in automotive engineering with safe driving functions, the sensor system is intended to deliver three-dimensional images with a high angular resolution of 0.1 degrees and below, with high insensitivity to environmental interference.This cannot be achieved with conventional radar technology according to the prior art, as the resolution of such systems is too low. This is precisely where the sensor system according to the invention advantageously comes into play. The sensor system can be configured as a photonic radar sensor device, which increases resolution by co-integrating electronic and photonic components on a single semiconductor chip. Tracking of the FMCW signal, as well as all signal processing and evaluation, are performed centrally in the central station. Each transmit and receive module features an electronically and photonically co-integrated chip, a so-called Epic chip. Silicon photonics technology is used for this co-integration. This technology enables the monolithic integration of photonic components, high-frequency electronics, and digital electronics on a single chip. The technical innovation of such a system lies in the transmission of gigahertz signals using the optical carrier signal in the terahertz frequency range.A central station, which can also be described as a central electronic computing unit, generates an optical carrier frequency in terahertz. The transmitted signal is modulated onto this carrier frequency with one-eighth of the radar frequency and sent via optical fiber to the antenna chips. Frequency multiplication takes place on the antenna chips, enabling them to emit radar radiation. Signal detection occurs in reverse. All data is processed at the central station. However, such a design is very complex to implement gigahertz electronics at the chip level. In particular, the frequency multiplication that takes place on the chip after detection by a photodiode is technically challenging and poses a significant challenge in generating a gigahertz signal with a high signal-to-noise ratio and minimal jitter. The gigahertz signal must then undergo further complex stabilization steps. Moreover, gigahertz electronics are expensive. Furthermore, high power requirements are placed on the optical substrate, especially the laser, as a great deal of optical power is needed to generate a highly precise gigahertz signal. This makes single-phase ring lines for a radar array with many distributed radar semiconductor chips difficult to implement.In particular, two photonic-electronic semiconductor chips are still required for each transmit and receive channel, which leads to further costs. The sensor system according to the invention solves at least some, and in particular completely, the problems mentioned above. In particular, the invention utilizes the fact that the radiation from the laser device, which can also be configured as a CW laser, is coupled into a photonic semiconductor via an optical interface. This can be the optical transmission signal or a carrier signal of the CW laser. The generation of the FMCW signal, as well as all signal processing and evaluation, is performed by a central station, such as the computer unit. Each transmit and receive module consists of an electronically and photonically cointegrated chip (so-called "EPIC chip"). Silicon photonics technology is used for the cointegration. This enables the monolithic integration of photonic components, high-frequency electronics, and digital electronics together on a single chip ("electronic-photonic cointegration"). The technical innovation of such a system lies in the signal transmission of GHz signals using an optical carrier signal in the THz frequency range. A central station generates an optical carrier frequency (THz). The signal to be transmitted is modulated onto this carrier frequency at 1 / 8 of the radar frequency and sent to the antenna chips via optical fiber.The frequency is amplified eightfold so that the radar radiation can be emitted by the antenna chips. Signal detection occurs in reverse. All data is processed at the central station. The principle of electronic-photonic cointegration in a single chip, with silicon-on-insulator regions for the photonic components and bulk silicon regions for the electronic circuits, is a globally unique technology. Particularly at high data rates, this enables high signal quality with minimal parasitic interference. The connection of the RF circuits for the radar antennas, including the frequency multiplier, to the optical transceiver can be implemented without additional wire or flip-chip bonding. Furthermore, chips can be optically and electrically tested at the wafer level, resulting in a high yield in subsequent module assembly. This technology allows for extremely compact form factors and is therefore highly relevant for the application of silicon photonics-based optical technologies in the automotive industry. The hurdle to the productive use of optical fibers lies in the lack of scalability of currently available technologies. This scalability to large volumes is made possible by the technology for highly integrated manufacturing of electronically and photonically integrated circuits. The result is a significant reduction in assembly costs and a more efficient cost structure. Extensive libraries of electronic and photonic components for high-bandwidth data transmission, developed from data center solutions, are being utilized in this project. For example, the sensor system, particularly for environmental detection, can be configured with: In particular, an optical device for generating an optical carrier signal, a transmitter which has several transmitter units, wherein: In particular, the transmitter is configured to transmit electrical output signals based on the optical carrier signal, comprising: In particular, a first transmission path of the transmitter which is configured to provide a first electrical output signal based on the optical carrier signal to a first transmitter unit of the several transmitter units which is arranged on the first transmission path; In particular, at least one second transmission path of the transmitter, different from the first transmission path, which is configured to generate a second electrical output signal based on the optical carrier signal and to transmit it to a second transmitter unit of the several transmitter units.which is arranged on the second transmission path, wherein - In particular, the transmitting device is configured to generate the second electrical output signal such that the second electrical output signal has a second frequency different from a first frequency of the first electrical output signal, and - In particular, the transmitting device is configured to transmit the first electrical output signal with the first transmitting unit and the second electrical output signal with the second transmitting unit simultaneously in a transmission process. Another aspect of the invention relates to a vehicle with a sensor system according to the preceding aspect or an advantageous further development. For example, the vehicle could be a manually operated vehicle, a partially autonomous vehicle, or a fully autonomous vehicle. In other words, the vehicle could be a highly automated vehicle. In particular, the vehicle may be a motor vehicle, such as a passenger car or truck. For example, the sensor system could include a real antenna array, which in turn comprises several antenna elements, such as transmitting and receiving antennas, distributed across the vehicle at intervals. These could, for instance, be located in the area of the vehicle's B-pillar. This allows for the most efficient possible detection of the vehicle's surroundings. The distributed arrangement of the individual antenna elements on the vehicle enables, in particular, 360-degree surround-view detection. For example, the antenna elements of the antenna array can be configured in a sparse array configuration. In particular, the antenna elements of the antenna array can be arranged on the vehicle in a sparsely populated or lightly populated configuration. Exemplary embodiments of individual aspects of the invention can be considered advantageous embodiments of other aspects. In particular, the respective exemplary embodiments of individual aspects can be regarded as advantageous embodiments of all other aspects. The reverse is also true. Advantageous embodiments of the method(s) are to be regarded as advantageous embodiments of the sensor system and the vehicle. The sensor system and the vehicle possess tangible features that enable the implementation of the method or an advantageous embodiment thereof. For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that, according to the procedure, an error message and / or a request for user feedback is issued and / or a default setting and / or a predetermined initial state is set. The invention also includes further developments of the sensor system and the vehicle according to the invention, which have features already described in connection with the further developments of the method according to the invention. For this reason, the corresponding further developments of the sensor system and the vehicle according to the invention are not described again here. The invention also includes combinations of the features of the described embodiments. The following describes exemplary embodiments of the invention. To this end: Fig. 1 shows a schematic representation of a vehicle with a sensor system comprising antenna elements of an antenna array distributed throughout the vehicle; Fig. 2 shows a schematic block diagram of the sensor system from Fig. 1; Fig. 3 shows a schematic representation of the vehicle from Fig. 1, where a real antenna array and a virtual antenna array for environmental sensing are shown; Fig. 4 shows an exemplary representation of the vehicle during a journey, wherein simultaneous transmission of frequency-shifted signals takes place at the respective measurement positions in order to generate a grid model with respect to the space to be reconstructed; Fig. 5 shows a schematic representation of the frequency-shifted electrical output signals of the transmission process; Fig. 6 shows, starting from Fig.5 shows a further representation of the electrical outgoing signals, where the signals overlap in modulation ranges; Fig. 7 shows a schematic representation of the transmitter, which may include several transmitting antennas; Fig. 8 shows a schematic representation of the receiver, which may, for example, have several receiving antennas; Fig. 9 shows an exemplary representation of the virtual antenna array, which may have a multitude of virtual receiving antennas generated by a computer; Fig. 10 shows a schematic representation of partial spectra of a distance spectrum of a virtual receiving antenna; Fig. 11 shows a schematic representation of the grid model for environmental reconstruction, where information is transferred to individual areas of the grid model based on the partial spectra; Fig. 12 shows, starting from Fig.Figure 11 shows a detailed view of how the individual sub-spectra are projected into the grid model; Figure 13 shows schematically how the respective sub-spectra are filtered with respect to the grid model in order to compensate for the respective phase positions with respect to the grid model; and Figure 14 shows an exemplary procedure for environmental reconstruction based on a virtual antenna array. The embodiments described below are preferred embodiments of the invention. In these embodiments, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described. In the figures, functionally identical elements are each provided with the same reference symbols. Figure 1 shows various schematic views (front view, rear view, side view) of a vehicle 1, which may be a motor vehicle. The vehicle 1 includes, for example, a sensor system 2. Sensor system 2 could, for example, be a radar system or an environmental sensor system of vehicle 1. Sensor system 2 could be communicatively networked with one or more driver assistance systems or other vehicle systems. For example, sensor system 2 could be a radar sensor, a lidar sensor, or another type of sensor, particularly for vehicles. In addition to its use in vehicle 1, sensor system 2 could also be used in external systems. For example, the sensor system 2 has at least one antenna array or several antenna arrays. The antenna array can in turn be formed from a multitude of antenna elements, such as several transmitting antennas 3 and several receiving antennas 4. The antenna elements can be arranged at intervals from one another on the vehicle 1, particularly for 360-degree environmental sensing. Figure 2 shows a possible embodiment of the sensor system 2. The sensor system 2 can comprise at least one radar sensor device 5 and a central electronic computing unit 6. For example, the radar sensor device 5 and the central electronic computing unit 6 can be separate and physically distinct units. The radar sensor device 5 can, for example, comprise at least one antenna array. Alternatively, the antenna array can function as the radar sensor device 5. The central electronic computing unit 6 can be a central processing unit. For example, the central electronic computing unit 6 can generate an electrical control signal with which a laser device 7 can be driven or controlled. The laser device 7 can, for example, be a CW laser. With the aid of the laser device 7, an optical transmission signal or a carrier signal 8 can be generated. The optical transmission signal 8 can, in particular, be described as an optical carrier signal in the terahertz frequency range. The central electronic computing unit 6 can, for example, generate the optical carrier frequency. The signal to be transmitted is modulated onto this optical carrier frequency with one-eighth of a radar frequency and transmitted, for example, to the radar sensor device 5. In this way, an eightfold frequency amplification can take place.Again, with the help of the radar sensor device, 5 signals in the gigahertz frequency range can be received and transmitted to the central electronic computing unit 6. For example, the central electronic computing unit 6 can be coupled to an optical input 10 and an optical output 11 of the radar sensor device 5 via at least one optical fiber 9. This allows bidirectional signal transmission between the central electronic computing unit 6 and the radar sensor device 5. For example, the central electronic computing unit 6 can be referred to as the electronic evaluation unit. The central electronic computing unit 6 can further comprise an optical receiver 12, which is configured to receive an optical output signal 13 provided by the optical output 11 of the radar sensor device 5. Thus, the central electronic computing unit 6 can be coupled to the radar sensor device 5 via optical fiber or an electronic interface, such as Ethernet. In particular, several radar sensor devices or antenna arrays can be coupled to the central electronic computing unit 6. For example, the central electronic computing unit 6 can comprise a processing unit 14, or a computing unit, with which the received optical output signal can be processed. This allows signal acquisition and subsequent data processing of the received output signal 11 to be performed. In particular, the central electronic computing unit 6 can have or provide all necessary control signals, data processing signals, modules and interfaces. For example, the radar sensor device 5 can, in addition to the optical input 10 and the optical output 11, have at least one transmitter 15, which can be one of the transmitting antennas 3, and at least one receiver 16, which can be one of the receiving antennas 4. Thus, the radar sensor device 5 has a receiver module and / or a transmitter module. In particular, the transmitter 15 and the receiver 16 can be integrated on one and the same chip. It is also conceivable that they are located on different semiconductor chips. With the aid of the transmitter 15, an electrical radar transmission signal 17, which is based on the optical transmission signal 8, can be transmitted into the vicinity 18 of the vehicle 1. Thus, a corresponding radar signal 17 can be transmitted depending on the optical transmission signal 8. If this signal 17 is now reflected in the vicinity 18 by objects such as road users, roads, trees or other objects, an electrical reception signal 19 corresponding to the electrical radar transmission signal 17 and reflected in the vicinity 18 can be received. For example, the transmitting device 15 can have at least one antenna or antenna unit or several antennas for transmitting. For example, the transmitted radar signal 17 or electrical signal and the received signal 19 can be in the terahertz or gigahertz frequency range. Thus, the sensor system 2 can be used to frequency-convert a terahertz carrier signal, in particular a transmission signal 8, into the gigahertz frequency range for transmission. Conversely, gigahertz signals can be received by modulation onto a terahertz carrier signal. For example, the transmitting device 15 can have at least one grid coupler and one photodiode for transmission. The receiving device 16 can, for example, have two jitter couplers, one photodiode, and one modulator for reception. Sensor system 2 can modulate at 1 / 8 of the radar frequency and transmit the signal via optical fiber to the antenna chips or antenna elements. These elements undergo a frequency multiplication of eight times, enabling the radar radiation to be emitted by the antenna chips. Signal detection can optionally be performed in reverse. All data can be processed at the central station. Fig. 3 shows another embodiment of the sensor system 2. Here, the sensor system also includes the computing device 6, which in this embodiment may have a different configuration or equipment. The sensor system 2 specifically features several transmit-receive units, such as the transmit and receive antennas 3, 4, which can be arranged distributed on the vehicle 1, for example, especially for environmental detection. The transmit-receive units or antenna elements are applicable for both transmitting and receiving signals. Therefore, these transmit-receive units are combined units for both transmitting and receiving signals. In particular, such a transmit-receive unit can be referred to as a transmit and receive module. This can be formed from an electronically photonic co-integrated chip (so-called "EPIC chip"). The computing unit 6, which can be referred to as the central processing unit, can also be formed from an electronically photonic co-integrated chip. In particular, the computing unit 6 is a physically and / or spatially separate unit from the transmit-receive units. For example, the computing unit 6 can include an optical unit, or the laser unit 7, or a laser. In particular, the optical unit can be configured as an optical source or as a CW laser. The optical unit can generate and thus provide the optical transmission signal 8, or a carrier signal. The optical transmission signal 8 can, in particular, be configured as an optical carrier signal in the terahertz frequency range. The computing unit 6 can, for example, generate the optical carrier frequency. The signal to be transmitted can be modulated onto this optical carrier frequency with one-eighth of a radar frequency and, for example, transmitted to the transceiver units. In this way, frequency multiplication can take place. Signals in the gigahertz frequency range can then be received using the transceiver units. For example, the computer 6 can be connected to a respective transmit-receive unit via fiber optic cable 9, forming an optical transmission link. Signals, particularly optical signals, can be transmitted from the computer 6 to the individual transmit-receive units via fiber optic cable 9. To enable received signals from the transmit-receive units to be sent back to the computer 6 for evaluation or signal processing, each transmit-receive unit can be optically coupled to the computer 6 via an optical return channel 20. With at least one of the transmit-receive units, the electrical outgoing signal 17 can be transmitted, in particular into the environment 18. Likewise, a corresponding electrical receive signal 19 can be received by the transmit-receive unit. For example, the outgoing signal 17 can be reflected by an object in the environment 18 of the vehicle 1 and thus received as an electrical receive signal 19. The receive signal 19, which can be described, for example, as a radar signal, can be transmitted to the computer 6 for evaluation or signal processing. For this purpose, the electrical receive signal can be converted into an optical receive signal 21 by means of the transmit-receive unit. For example, this can be transmitted via the return channel 9 of the computer 4. By means of an opto-electrical converter unit 22 or...The optical received signal 21 can be converted into an electrical signal 23 by the detector unit of the computing unit 6. Unit 22 can be used, for example, for optical detection. This conversion can be performed, for example, by homodyne detection or heterodyne detection. Furthermore, unit 22 can perform a phase measurement and / or a phase length measurement. Subsequently, digitization can be performed via a digital interface 24. This primarily involves analog-to-digital conversion. For this purpose, the digital interface 24 can include an analog-to-digital converter. A processing unit 14 can then be arranged. This unit can be used, for example, for signal processing, particularly for low-level signals. A Fast Fourier Transform (FFT) can be used for this purpose. The digitized, processed electrical signal 23 can then be made available to a CPU 25 of the computing unit 6. In this case, radar information or environmental information contained in the electrical signal 23 can be evaluated or processed.Furthermore, an electrical return channel 26 can be provided, which provides feedback from at least one of the transmit-receive units to the computing unit 6 and in particular to the digital interface 24. To achieve the most stable and low-noise environmental sensing or detection possible by the sensor system 2, the optical transmission signal 8 can be adapted using frequency synthesis or gigahertz frequency synthesis. For this purpose, the computing unit 6 can include a synthesis unit 27. The optical transmission signal 8 can be fed to or transmitted to the synthesis unit 27. For example, modulation can be performed before the optical transmission signal 8 is made available to the synthesis unit 27. A modulator or modulation unit 28 can be provided for this purpose. This can be configured, for example, as an arbitrary waveform generator or arbitrary function generator (AWG). An optical control unit 29 and an optical switch can be connected after the synthesis unit 27.Distributor 30 is provided in the computing unit 6 to supply appropriately processed signals from the synthesis unit 27 to the transmit-receive units via the optical fiber 9. Furthermore, a control unit 31 can be controlled by the evaluation unit 25, in particular to monitor and control the generation of the optical transmission signal. Additionally, a control unit or a feedback loop 32 can be provided. Furthermore, the computing unit 6 is electrically connected to the transmit-receive units by means of an electrical transmission link 33. An electrical control signal 34 can be transmitted via this electrical transmission link 33 to control or activate the transmit-receive units or antenna elements 4. In particular, the computing unit 6 serves to generate an optical carrier signal, the optical transmission signal 8, and to feed this signal into a gigahertz frequency synthesis unit, e.g., the synthesis unit 27. The synthesized gigahertz signal can be transmitted in the optical spectral range via fiber, i.e., the optical fiber 9, to the transmit-receive units, so that, for example, a 77 gigahertz signal can be emitted or transmitted by the transmit-receive units. Signal detection, in turn, can be carried out in reverse. All data can be processed or handled in the computing unit 6. In the illustration in Fig. 3, the optical carrier signal 8 can be described as an optically frequency-modulated carrier signal. This can be fed into a gigahertz frequency synthesis unit, such as synthesis unit 27, and the synthesized gigahertz signal can be forwarded in the optical spectral range to the transmitting device 15, for example, to be emitted as a 77 GHz signal. Figure 4 illustrates an exemplary embodiment of the present invention. The present invention is particularly advantageous when it is necessary to detect the spatial extent of objects in the vicinity of the vehicle 1. In other words, the vehicle 1 is in motion and, for example, follows a trajectory 35. For example, several transmitting antennas 3 and receiving antennas 4 can be arranged as a real antenna array 36 in the area of the vehicle 1, enabling environmental sensing to be performed laterally to the vehicle 1. Furthermore, the sensor system 2 can have additional transmitting and receiving antennas, which, as already explained, can be distributed around the vehicle 1. Advantageously, the invention allows for the reliable detection of outgoing structures in the vehicle's environment and an estimation of the height profiles of these structures. For this purpose, an environmental reconstruction, in particular a three-dimensional environmental reconstruction of the environment 18, is performed. A virtual, spatial grid model 37 is used here. As shown by way of example in Fig. 4, this virtual grid model 37 can consist of rectangular or cuboid volume pixels. Since the real antenna array 36 may be sparsely populated due to cost and / or space reasons, a virtual antenna array 39 is generated for the creation or generation of the grid model 37 and especially for the environmental reconstruction. The following figures explain how environmental reconstruction can be performed so that target information for target objects in the environment 18 can be determined based on this reconstruction. Figure 5 shows various frequency waveforms of external electrical signals 40 to 43. For the computer-based generation of the virtual antenna array 39, the electrical outgoing signals are transmitted simultaneously into the environment 18. These electrical outgoing signals can in turn be transmitted temporally by the transmitting antennas 3, in particular the transmitting antennas of the real antenna array 36. As shown by way of example in Fig. 5, each transmitting antenna 3 transmits the electrical outgoing signals 40 to 43 in one transmission process or transmission cycle. As shown in Fig. 5, these electrical external signals 40 to 43 are frequency-shifted relative to each other. In particular, these electrical external signals 40 to 43 can be described as frequency-modulated signals; more specifically, the electrical external signals 40 to 43 can be based on the optical signal 8. For example, Fig. 5 shows that each transmitted signal, i.e., signals 40 to 43, can be provided as a Sharp sequence via frequency modulation. Each transmitting antenna 3 transmits a frequency-modulated signal whose frequency differs from the transmitting frequencies of the other transmitting antennas by the frequency deviation Δf. For example, the following can be defined as the transmitter signal with regard to the electrical external transmission signals 40 to 43: The phase modulation for each transmitting antenna 3 can be mathematically described using the following equations. The following formula can be used to determine the slope of the frequency ramp. The previously used variables are described below. f0 Carrier frequency Δf Frequency deviation α Slope of the frequency ramp TCH Modulation duration of a chirp sT(t) Transmitted signal ΦK-1(c) Phase modulation of a respective transmitting antenna Figure 6 shows an alternative method for generating or providing the electrical output signals 40 to 43. Unlike the configuration in Figure 5, the electrical output signals 40 to 43 can be configured with overlapping modulation ranges. This approach allows for the coverage of several overlapping frequency bands and the creation of larger virtual devices. The other details relating to Figure 5 apply analogously here. Figure 7 illustrates, for example, how the transmitting device 15, to which the respective transmitting antennas 3 may belong, can be configured. Any number of transmitting antennas 3 can be associated with the transmitting device 15. As shown in this illustration, the transmitting antennas 3 can be arranged on a chip or on a circuit with respect to the transmitting device 15. It is also conceivable that the transmitting antennas 3 are separate units and thus arranged as separate electrical circuits. For example, the optical carrier signal 8 can be provided and converted into an electrical or electronic signal by means of a photodiode 44. This results in a corresponding electrical or electronic signal which can then be used as the basic transmit signal for modulating the individual electrical output signals 40 to 43. This basic electrical transmit signal can optionally be amplified by means of an amplifier or electronic amplifier 45. For example, each transmitting antenna 3 can be assigned to a specific transmitting path, so that a corresponding electrical output signal 40 to 43 can be provided for each transmitting path. For this purpose, frequency conversion units 46 to 48 can be provided upstream of each transmitting path and thus of each transmitting antenna 3. With a respective frequency conversion unit 46 to 48, or a respective frequency converter, the optical carrier signal 8, converted into an electrical range, can be frequency-modulated for a respective transmitting antenna 3, so that each transmitting antenna 3 emits a signal that is frequency-shifted compared to the other signals.Thus, in a respective transmission path, by means of a respective frequency conversion unit 46 to 48, the frequency deviation by which the respective electrical outgoing transmission signal 40 to 43 differs at each transmitting antenna 3 can be generated depending on the optical carrier signal 8. In particular, the electrical outgoing signals 40 to 43, which are frequency-shifted relative to each other, can be transmitted from all transmitting antennas 3, especially the transmitting antennas of the real antenna array 36, per transmission process. As already mentioned, the vehicle 1 can be a moving vehicle along a trajectory 35. Thus, a transmission process can be carried out at specific measurement positions 49 (see Fig. 4). In this way, a transmission process can be carried out in relation to the various measurement positions 49, in which, in particular, frequency-shifted electrical outgoing signals 40 to 43 can be transmitted from all transmitting antennas 3. Figure 8 shows a further embodiment of the receiving device 16. Similar to the transmitting device 15, either all receiving elements 4 can be arranged on a single chip or integrated circuit (IC), or each receiving antenna 4 can have its own chip. Each receiving antenna 4 can be assigned its own receiving path. An electrical amplifier can be arranged for each receiving path, and thus after each receiving antenna 4. For example, each incoming received signal 54 to 57 can be mathematically modulated as a superposition of the time-delayed and frequency-divergent electrical outgoing signals 40 to 43. The frequency-modulated original signal, in particular the optical carrier signal 8, can be used as the reference signal for the mixing process.This process can be carried out, for example, by means of an electronic unit 85, which may be a "mixer". For this purpose, as shown by way of example in Fig. 8, the respective received signals 54 to 57 can be supplied to the unit 58. Additionally, a carrier signal 59 can be supplied to the unit 58. The carrier signal 59 can be converted from the optical carrier signal 8, in particular by a photodiode 60. Subsequently, a corresponding signal can be transmitted from the unit 58, for example, to the computing device 6. For example, the beat signal considered for further processing can be generated by an I / Q modulation (not shown here). In other words, such a beat signal can be generated for each received signal 54 to 57. For example, such a beat signal can be defined as follows. The following definitions apply to the variables below: τ Time delay t Index receiving antenna k Index transmitting antenna K Number of transmitting antennas sB(t,l) Beat signal Figure 9 below schematically illustrates how the virtual antenna array 39 is generated based on the temporally transmitted electrical signals 40 to 43, for example by means of the transmitting device 15, and the received signals 54 to 57, for example by means of the receiving device 16. In particular, the virtual antenna array 39 can be designed based on the antenna manifold of the underlying physical or real transmitting / receiving antennas 3, 4. For example, the virtual antenna array 39 can have a plurality of virtual receiving antennas 61. The virtual antenna array 39 offers the advantage, in particular, that it has a larger number of virtual receiving antennas 61 compared to the real antenna array 36. At the very least, the number of virtual receiving antennas 61 is many times greater than the number of real receiving antennas 4. Furthermore, as shown, for example, in Fig. 9, the virtual antenna array 39 can be structured as a logical group characterized by the physical antenna positions of a receiving antenna 4 and all transmitting antennas 3. In particular, the virtual antenna array 39 can be generated based on the received electrical signals 54 to 57, the real antenna positions of the transmitting antennas 3, and the real antenna positions of the receiving antennas 4. The underlying received signal of a respective virtual receiving antenna 61 can, for example, correspond to the beat signal explained in Fig. 8. Figure 10 shows, for example, the corresponding generated distance spectrum 62, or range spectrum, for a virtual receiving antenna 61. This distance spectrum 62 can be described, for example, by the following formula: To determine the distance spectrum 62, the electrical and, in particular, the mixed received signals 63 associated with this virtual receiving antenna 62 can be taken into account. Due to the frequency conversion of the optical carrier signal 8 by an integer multiple of the bandwidth chirps, the distance spectrum 62 of the underlying receiving channel or receiving antenna 61 can be separated by the applied frequency deviation. In other words, as shown in Fig. 10, sub-spectra 64 to 67 can be generated or separated. In other words, the distance spectrum 62 is decomposed or separated into several sub-spectra 64 to 67. These sub-spectra can represent different spectral ranges of the distance spectrum 62. In particular, emitted signals, i.e., the outgoing signals 40 to 43, can be assigned to the spectral range within the spectrum of a virtual receiving channel. In other words, different electrical outgoing signals 40 to 43 can be received by the respective receiving antenna 4 and thus by the respective virtual receiving antenna 63.These signals, in turn, each exhibit a different frequency deviation relative to one another, so that, based on this, the transmitted signals 40 to 43 are decomposed into sub-spectra in the virtual receiving antenna according to their respective frequency deviations. In other words, each of these sub-spectra 64 to 67 can be selected with respect to the different frequencies or bandwidths of the transmitted signals 40 to 43. For example, the transmitted signal 43 can be considered corresponding to sub-spectrum 64, the transmitted signal 62 to sub-spectrum 65, the transmitted signal 41 to sub-spectrum 66, and the corresponding transmitted signal 40 to sub-spectrum 67. Figure 11 below illustrates how the distance spectrum 62 of a virtual receiving antenna 61 can be projected onto a respective volume pixel 38 within the three-dimensional grid model 37 using a projection principle. The projection is based, for example, on a linear interpolation of the distance spectrum 62 as a function of the time delay, which corresponds to the volume pixel coordinates in the grid model 37 due to the distance between the transmitting antenna 3 and the virtual receiving antenna 61. In other words, the spectral value of each subspectrum 64 to 67 is projected onto the spatial coordinate corresponding to the distance within the grid model 37. The distance spectrum 62 can therefore contain distance information. In particular, a relationship can be established here, which can be considered based on the respective measurement positions 49 during a given transmission process. As illustrated by example in Fig. 11, the position, especially the relative position, of the respective transmitting antenna 3 can be considered for assigning each subspectrum 64 to 67 to a volume pixel 38. As illustrated by example in Fig. 4, the vehicle 1 moves along the trajectory 35, and signals can be transmitted and received at the respective measurement positions 49 in relation to the trajectory 35. Thus, as shown in Fig.As shown schematically in Figure 4, a sub-area 68 of the filter model 37 is generated for each measurement position 49. If the vehicle 1 then continues driving, another sub-area of the spatial grid 37 can be generated for the next measurement position 49. Thus, a reconstruction of the environment 18 can be carried out. The following equations can be used to describe a projection of the spectral value onto a spatial coordinate corresponding to the distance within the grid model. Figure 12 illustrates how the respective sub-spectra 64 to 67 can be projected, instructed, or incorporated into the grating model 37. This allows for environmental modulation or reconstruction. Figure 13 illustrates how compensation for the distance-related fiber position of the projected subspectroscopy 64 to 67 on the grating model 3 can be performed with respect to the ambient modulation. This can be achieved through a filtering process, specifically phase compensation filtering. For this purpose, the subspectra 64 to 67 of each virtual antenna element 61 can be filtered. The phase of the projection can depend on the superposition of the phases resulting from the distance of the transmitting antennas 3 to the volume pixel coordinate and the receiving antenna 4. Therefore, the filter for compensating this phase can take these influencing factors into account. Additionally, the individual frequency response of the corresponding transmitting antenna 3 can also be considered. After filtering, the filled projections, and thus the filtered subspectra 64 to 67, can be integrated. For this purpose, a filter function h(I) can be used, for example, to compensate for the phase of individual sub-spectra, as can be described by the following equations. Influencing factors can include the antenna positions of all transmitting antennas 3, the antenna position of the receiving antenna 4 under consideration, and the transmission frequency along with the transmitting antenna. The running index I refers to the currently considered virtual receiving antenna 61. This filter function can therefore be used to perform phase image compensation filtering. Figure 14 illustrates an exemplary process regarding the environment for the construction using, for example, laterally mounted antenna arrays in vehicle 1. In an optional step S10, a MIMO method can be applied. This is done by simultaneously transmitting frequency-converted or frequency-shifted signals, such as the electrical external signals 40 to 43. This step S10 primarily takes place at a measurement position 49. This measurement position can, in turn, have the coordinates X, Y, Z. In a subsequent optional step S11, after the simultaneous emission of the electrical transmit signals 40 to 43, the corresponding receive signals 54 to 57 can be received. The received signal 54 to 57 can then be mixed by multiplying it with the carrier signal 59. In the optional subsequent step S12, a range spectrum or distance spectrum 62 can be calculated for each virtual receiving antenna 61. Subsequently, in an optional step S13, the frequency spectrum or the distance spectrum 62 can be decomposed into the sub-spectra 64 to 67 depending on the frequency shifts and assignment of the corresponding transmitting antennas 3. In a subsequent optional step S14, the projection of the partial spectra 64 to 67 of the virtual receiving antenna 61 onto the spatial grid model 37 in relation to the current measurement position 94 can then take place. In a subsequent optional document S15, a calculation of a phase compensation filter for phase compensation of the projected subspectroscopy 64 to 65 can be performed. The receiving position of the virtual receiving antenna 61, the position of the corresponding transmitting antenna 3, and the transmit frequency with respect to this corresponding transmitting antenna 3 can be taken into account. In a subsequent step S16, the compensation of the phase position within the spatial grid model 37 can be carried out for each subspectroscopy 64 to 67. In a subsequent step S17, an integration of the filtered projections of all sub-spectra 64 to 67 can be carried out. In a subsequent step S18, steps S14 to S17 are carried out for each of the virtual receiving antennas 61. After the partial spectra 64 to 67 for each virtual receiving antenna 61 at this measurement position 49 have been projected into the grid model 67, the integration of the filtered projection of all virtual receiving antennas 61 can be carried out in an optional step S19. Finally, in the next step S20, steps S10 to S19 can now be carried out for the subsequent measurement position 49 along trajectory 35. In other words, steps S10 to S19 are carried out for each measurement position and thus for each transmission process. The following optional steps describe the invention in other words for reconstructing a captured three-dimensional environment by constructing a synthetic aperture and reconstructing the received signals by a virtual antenna array along the trajectory 35 of a vehicle 1: 1. Fully coherent 3D sensor along the vehicle's B-pillar; 2. Simultaneous transmission of frequency-modulated transmit signals (output signals 40 to 43) of different frequencies from all transmitting antennas 3; 3. Generation of a virtual antenna array 39 by applying the MIMO method; 4. Mixing the received signal 54 to 57 of each virtual receiving channel (receiving antenna 61) with the original transmitted signal (carrier signal 59), which is not subject to any further frequency conversion; 5. Repeating the transmission process at equidistant intervals to construct a synthetic aperture; 6. Calculation of the range spectrum 62 for all virtual receiving channels; 7.Decomposition of the range spectra as a function of the frequency shifts of each transmitting antenna 3; 8. Projection of the resulting sub-spectra 64 to 67 of each virtual channel onto a discrete three-dimensional volume grid 37 as a function of the transmitting antenna corresponding to the sub-spectrum; 9. Back-projection by filtering the association of volume pixel 38 and projected spectral value from range spectrum: a. Filter calculation based on measurement position 49 corresponding transmitting antenna position, transmit frequency, 3D coordinate of the volume pixel and virtual receiving antenna 61 b. Application of the filter to the phase of the corresponding volume pixel c. Storage of the filter value in a data structure equivalent to the three-dimensional space grid model for each sub-spectrum 10.11. Integration of the data structures of each subspectroscope, so that each virtual receive channel can be assigned a filtered data structure corresponding to a measurement position and the spatial grid model at that measurement position; 12. Execution of steps (7), (8), and (9) for each virtual receive channel; 13. Integration of the data structures of the backprojected three-dimensional spatial grid models of all virtual receive channels. Each measurement position is thus assigned a spatial grid model and a data structure composed of the sum of the filtered spectral projects onto that spatial grid model; 14. Repeating steps (5) to (11) for each new measurement position; 15. Integration of the magnitudes at the same spatial grid coordinates across all measurement positions. In other words, the present invention enables the construction of a synthetic apparatus and the reconstruction of the detected environment 18. For this purpose, the vehicle 1 can generate a virtual antenna array within a measurement cycle and detect the environment 80 laterally to the vehicle direction at equidistant intervals. In other words, at each measurement position 49, a detection process is performed, followed by a signal processing operation. A three-dimensional grid model, such as the grid model 37, of the environment 18 serves as the basis for the spatial projection of the distance spectrum of received signals and as the basis for the reconstruction of a three-dimensional amplitude map for capturing spatially extended structures.Thus, with the help of the filled or information-enhanced grid model 37, an improved detection of the environment, in particular of the spatially extended structures within it, such as target objects, can be achieved. In particular, the transmitting antennas 3 and the receiving antennas 4 can be arranged as miniaturized, photonically cointegrated radar chips in a coherently distributed, thinned array 36 along the vehicle's B-pillar. By simultaneously transmitting frequency-modulated signals with different frequency deviations, the virtual antenna array 39 can then be generated for each transmission cycle using the MIMO method. Subsequently, measurements at spatially equidistant intervals can be taken to determine the measurement positions 49 for the construction of a synthetic aperture and the reconstruction of the environment 18 into a three-dimensional environmental map, such as the grid model 37. Reference symbol list1 Vehicle 2 Sensor system 3 Antenna array 4 Antenna elements 5 Radar sensor device 6 Central electronic computing unit 7 Optical device 8 Optical carrier signal 9 Fiber optic cable 10 Optical input 11 Optical output 12 Receiver unit 13 Output signal 14 Processing unit 15 Transmitter 16 Receiver unit 17 Electrical outgoing signal 18 Environment 19 Electrical received signal 20 Return channel 21 Optical received signal 22 Opto-electrical converter unit 23 Electrical signal 24 Digital interface 25 CPU 26 Electrical return channel 27 Synthesis unit 28 Modulator 29 Optical control unit 30 Optical distributor 31 Control unit 32 A feedback loop 33 Electrical transmission path 34 Electrical control signal 35 Trajectory 36 Virtual antenna array 37 Virtualspatial grid model 38 volume pixels 39 virtual antenna array 40 to 43 electrical outgoing signals 44 photodiode 45 amplifier 46 to 48 frequency conversion unit 49 measurement positions 50 to 53 amplifier 54 to 57 electrical receive signals 58 electronic unit 49 59 carrier signal 60 photodiode 61 virtual receiving antenna 63 distance spectrum 63 beat signal 64 to 67 sub-spectra S10 to S20 steps,
Claims
Method for determining at least one target information of a target object of a sensor system (2) which has several transmitting antennas (3) and several receiving antennas (4), wherein: - in a transmission process, several frequency-shifted electrical outgoing signals (40 to 43) are simultaneously transmitted from the several transmitting antennas (3) into an environment (18); - electrical receiving signals (54 to 57), which are based on the transmitted electrical outgoing signals (40 to 43), are received by the several receiving antennas; - on the basis of the received electrical receiving signals (54 to 57), the antenna positions of the several transmitting antennas (3) and the antenna positions of the several receiving antennas (4), a virtual antenna array (39) which has several virtual receiving antennas (61) is generated; - an environment reconstruction of the environment (18) is performed based on the virtual antenna array (39) is carried outand- which at least one target information is determined based on the environmental reconstruction, wherein- a respective received electrical receive signal (54 to 57), which is assigned to a respective virtual receiving antenna (61) of the virtual antenna array (39), is mixed with a carrier signal (59) on which the several frequency-shifted electrical transmit signals (40 to 43) are based, and- for each virtual receiving antenna (61) a distance spectrum (62) is determined on the basis of the received signal (54 to 57) belonging to the respective receiving antenna (61) and mixed with the carrier signal, characterized in thatthat a respective distance spectrum (62) of a respective virtual receiving antenna (61) is decomposed into partial spectra (64 to 67) depending on a corresponding electrical outgoing signal (40 to 43) to the received signal (54 to 57) and by the transmitting antenna (3) emitting this electrical outgoing signal (40 to 43). Method according to claim 1, wherein the partial spectra (64 to 67) of a respective virtual receiving antenna (61) are projected onto a virtual spatial grid model (37) relating to the environmental reconstruction, with which the environment (18) can be modulated three-dimensionally, depending on the transmitting antenna (3) corresponding to a respective partial spectrum of the partial spectra (64 to 67). Method according to claim 2, wherein the virtual spatial grid model (37) is divided into several volume pixels (38), wherein a respective partial spectrum of the partial spectra (64 to 67) of a respective virtual receiving antenna (61) is assigned to a volume pixel of the several volume pixels (38) on the basis of a relation between the corresponding transmitting antenna (3) and the virtual spatial grid model (37). Method according to claim 2 or 3, wherein a phase compensation filtering is carried out for a respective sub-spectrum (64 to 67) to compensate for a phase position of the respective sub-spectrum in the virtual, spatial grid model (37), wherein the phase compensation filtering of a respective sub-spectrum (64 to 67) is carried out on the basis of the transmitting antenna (3) corresponding to the respective sub-spectrum (64 to 67), the virtual receiving antenna (61) of the respective sub-spectrum (64 to 67) and a frequency of the electrical outgoing signal (40 to 43) emitted by the transmitting antenna (3) corresponding to the respective sub-spectrum (64 to 67). Method according to claim 4, wherein the individual partial spectra (64 to 67) of a respective receiving antenna (61) in which the phase compensation filtering was carried out are integrated. Sensor system (2) comprising multiple transmitting antennas (3), multiple receiving antennas (4) and an electronic computing device (6), wherein the sensor system (2) is configured to perform a method according to one of the preceding claims. Vehicle (1) with a sensor system (2) according to claim 6 .